How Do You Do A Convincing Shimmy

I've been playing for awhile at around 1400-1500 MR and have trouble opening people up in advantage. Unless I'm playing Akuma, I can't get people to whiff throw. Watching other people do it, it looks like the opponent is like half a second behind, but when I do it my opponents jab the instant I'm out of throw range. I spend my first half of each set getting throw teched so obviously I'm not very convincing with however I try to shimmy.

How do you guys do it so well?